Air bag passive restraint system has been mounted in a vehicle seat. Examples of such systems are shown in U.S. Pat. Nos. 5,112,079 and 5,348,342, both to Haland et al. However, known systems require the assembly of independent units one of which is an independent inflation housing attached to the frame or other support structure in the seat assembly. Yet another assembly is shown in U.S. Pat. No. 5,419,579 to McPherson et al wherein the bag and gas generator are disposed in a single sheet metal housing.